1. Field of the Invention
The invention relates to an assembly of a shoe and a retention element adapted to retain the leg of an athlete on a gliding board, and particularly the leg of a skier on a ski.
The invention likewise relates to a shoe and to a retention element of the assembly taken individually.
2. Description of Background and Material Information
In the case of alpine skiing, it is known to retain a shoe supported on the ski by means of a front retention or binding element and a rear retention or binding element which retain front and rear tips of the boot. These two binding elements comprise a jaw carried by a body. The jaw is movable in response to the biases of the boot against the return force of a spring which opposes displacement of the boot.
The rigidity of the spring is adjustable, in a manner such that the boot is freed from the binding element in response to a bias exceeding a predetermined bias threshold. This threshold beyond which the jaw lets the boot escape is normally referred to as a release threshold.
In order to be able to utilize boots with different binding or retention elements available on the market, the shape of the front and rear tips of the boot has been standardized. In the ISO standards system, the standard in effect is referred to as ISO 5355. As to the binding elements, they are adapted to be compatible with standardized zones of the boot and to assure the release of the boot at predetermined release values.
At the front, a boot is retained by a front binding element whose jaw is movable at least laterally towards the interior or exterior of the foot, which corresponds to a torsional bias on the leg of a skier.
Currently available bindings have a release threshold which is equal during movement towards both the interior and the exterior. Yet, it is known that the knee of the skier, which is biased during a torsional fall, is more fragile with respect to an interior rotation of the foot than in the case of rotation towards the exterior.
To take this into account, binding elements have been proposed which have a release threshold which varies depending on the direction in which the jaw rocks. Such elements are described, for example in French Patents 1503847, 1503848, and 1503849, and in German Patent Application No. 1807074.
The major disadvantage of this type of apparatus is that it requires a pairing between the shoes and the skis, i.e., the right and left skis must necessarily be identified and the skier must put the right ski on the right boot and the left ski with the left boot. He must certainly not reverse the skis when they are put on; otherwise, the reverse effect is obtained which can have serious consequences. Yet, according to the standards, the tips of the boot are symmetrical with respect to a vertical median plane. As a result, there would normally be no presumptive reason for distinguishing and identifying ski equipment as being right and left. However, for these particular bindings, it is thus necessary for the skier to pay attention to the manner in which he lines up his skis for putting them on. This represents a major risk of confusion and danger.